MR imaging uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of organs, soft tissues, bone and virtually all other internal body structures. The images can then be examined on a computer monitor or printed.
MRI of the breast offers valuable information about many breast conditions that cannot be obtained by other imaging modalities, such as mammography or ultrasound. Each exam produces hundreds of images of the breast, cross-sectional in all three directions (side-to-side, top-to-bottom, front-to-back).
MRI of the breast is not a replacement for mammography or ultrasound imaging but rather a supplemental tool for detecting and staging breast cancer and other breast abnormalities. 
Breast MRI is performed at the S. Mark Taper Foundation Imaging Center under the guidance of Rola Saouaf, MD, Chief of Body and Cardiac MRI.
MR imaging of the breast is performed to:
- evaluate abnormalities detected by mammography.
- identify early breast cancer not detected through other means, especially in women with dense breast tissue and those at high risk for the disease.
- screen for cancer in women who have implants or scar tissue that might jeopardize an accurate result from a mammogram.
- determine the integrity of breast implants.
- distinguish between scar tissue and recurrent tumors.
- assess multiple tumor locations.
- look for multiple tumors prior to breast conservation surgery.
- determine whether cancer detected by mammography or ultrasound has spread further in the breast or into the chest wall.
- determine how much cancer has spread beyond the surgical site after a breast biopsy or lumpectomy.
- assess the effect of chemotherapy.
- provide additional information on a diseased breast to make treatment decisions.
"MRI Beats Mammograms at Spotting Early Breast Cancer" (Health Day pdf)
